This invention relates to a method of detecting obstacles on railroad lines.
In manually controlled rail vehicles, it is incumbent upon the driver to continuously check whether the track ahead is free, and to initiate safety reactions if necessary. In automatically controlled, driverless rail vehicles, this function must be performed in a different manner. One possible solution is to design the route in such a way that no obstacles can occur. This can be accomplished through the use of elevated track beam structures, tunnels, or fences. Aside from subway systems, where tunnel construction is an inherent requirement, implementation is very costly. Another solution is to replace the observation performed by the driver by automatic obstacle detection from the train. Considerable problems may arise in curves, at entries into stations due to standing trains, and in the case of obstacles close to the route. Due to obstructions of view, obstacles are perceived so late that stopping of the train before the obstacle to avoid a collision is no longer possible. In addition, complex and expensive evaluation electronics are necessary to be able to perform a reliable evaluation of moving images of an unknown route at speeds in excess of 200 km/h.
It is therefore an object of the invention to provide a method of detecting obstacles on railroad lines which does not have the above disadvantages.
This object is attained by a method of detecting obstacles on railroad lines for automatically controlled, driverless rail vehicles, wherein sensors operating in the optical range, the infrared range or the radio-wave range are arranged along the railroad lines for observing the respective routes ahead of the automatically controlled, driverless rail vehicles traveling on the railroad lines, and wherein an automatic evaluation of the sensor output signals is performed which is used at least in part to control the automatically controlled, driverless rail vehicles.
One advantage of the invention is that the railroad lines are divided into given, known line sections, each of which is monitored by a respective sensor, whereby the evaluation process is simplified. If the sensors are designed as video cameras, for example, a comparison with still images may suffice for the evaluation.
Furthermore, as the line sections are known, simple masking can be performed. Obstacles outside a set route to be monitored are masked out using suitable masks.
The components required to carry out the method need to be installed essentially only once along the railroad lines rather than on all trains. Use can be made of existing components such as masts and telecommunications and power cables laid along the railroad lines. This provides a saving in cost, particularly at high train densities.
In a preferred embodiment of the invention, automatic obstacle detection is used as a substitute for or in addition to xe2x80x9cline-clearxe2x80x9d signaling. Conventional xe2x80x9cline clearxe2x80x9d signaling methods use axle counters. The axle counters count the axles of a passing train. One axle counter is located at the beginning of a line section to be monitored, and another at the end. If the axle counter at the beginning registers a train entering the line section, the latter will be closed for further trains. If the axle counter at the end registers a train leaving the line section, the latter will be cleared. Instead of or in addition to this relatively costly and complicated technique, automatic obstacle detection can be used. Automatic obstacle detection is coupled with a xe2x80x9cline-clearxe2x80x9d signaling facility. If no obstacles are detected, the respective line section will be cleared automatically.
Another advantage of the invention is that obstacles of any kind can be detected. This also includes persons on the railroad tracks, so that attempted sabotage, for example, can be detected at an early time and appropriate measures can be taken.
By the arrangement of sensors along the railroad lines, all available railroad lines can be monitored simultaneously. This makes it possible to detect obstacles at the earliest possible time. Appropriate measures to remove the obstacles can be taken at the earliest possible time. Delays caused by obstacles are thus minimized.
If video cameras are used for the sensors, these can be rigidly or movably mounted, for example. Furthermore, remote control can be implemented. From a center, a person can select one camera, for example the one that has just detected an obstacle and is drawing attention to itself by, e.g., an audible and/or visual alarm signal. The person can then remotely pan the camera, operate the zoom of the camera, and bring the object into focus.